Place sliced peaches into a 8×8 inch pan. Sprinkle cinnamon evenly on top of the peaches.
Generously sprinkle French vanilla cake mix on top of the cinnamon and peaches. Gently press the down on the peaches to create a nice even layer of cake mix.
Cut the stick of butter into several very thin slices. Make sure the top of the cake is completely covered with thin slices of butter.
Bake for 40 minutes. Let cake cool for about 10 minutes before serving. Serve with a scoop of vanilla bean ice cream and top with candied pecans.